Apparatus for forming brake drums



Feb. 18; 1930. w. N. BOOTH 1,747,463

I ABPARATUS FOR FORMING BRAKE DRUMS INVENTOR. Mum/4 A 1540 m y ATTORNEYS Feb. 1s,- 1930. w.'N.BooTi-| APPARATUS. FOR FORMING BRAKE DRUMS v Filed-M01124. 192s ash ets-psneet 2 INVEN TOR Mum/M! 54am A TTORNEY5 Feb. 18,1930.

w. N. BQOTH- I APPARATUS FOR FORMING BRAKE DRUMS e Sheds-Sheet s Filed March 24. 19 2s INVENTOR. I MLt/fiM/M 540 7/1 ATTORNEY.

Feb. 18, 1930.

W. N. BOOTH APPARATUS FOR FORMING BRAKE DRUMS Filed March 24. 1926 6 Sheets-Sheet 4 I N VEN TOR.

A TTORNEYS Feb. l8, 1930. w. N, Boo-m v 71,747,463

' ARPABATUS FOR FORMING BRAKE DRUMS-- Filed March 24. 1926 v ;6 Shqs'-Sheet 6 INVENTOR. Mu MM #300 r ATTORNEYJ Patented Feb. 18, 1930 UNITED STATES PATIENT. OFFICE WILLIAM N. BOOTH, 015 DETROIT, MICHIGAN, ASSIGNOR T0 KELSEY-HA Y ES WHEEL CORPORATION, OI DETROIT, MICHIGAN, A GORPORATION OF NEW YORK .AI'IARATUS FOR FORMING BRAKE DRUMS I Application filed March 24, 1926. Serial No. 97,065.

The invention relates to apparatus for forming brake drums and refers more par,- ticularly to presses for forming brake drums from sheet metal by a drawing operation. One of the objects of the invention is to provide an apparatus for forming a mechanically true brake drum having a concentric brake flange. Another object is to provide an apparatus having means for stripping or disengaging the brake drum from the plunger without distorting the brake 'drum. With these as well as other objects in view the invention resides'in the novel features of construction and combinations and arrangements'of parts as more fully hereinafter set forth. v

In the drawings Figure 1 is a sectional side elevation of an apparatus embodying my invention;

Figure 2 is a sectional side elevation of l the press forming part of the apparatus;

Figure 3 is a plan view thereof with the punch removed.

Figure 4 is a perspective View of oneof the strippers forming part ofthe press;

Figures 5, 6,7, 8 and 9 are sectional elevations showing the operation of the press;

Figure is a view similar to Figure 2 and showing a modified press. I

In general, the apparatus embodying my invention includes the press having the bed 1 and the ram 2. The bed supports the die 3 and the ram carries the punch 4 which is adapted to cooperate with the die to draw a sheet metal blank into a brake drum.

The die comprises the die block 5 having the axial flared opening 6 and the concentric die block 7 set into the die block 5 and having the axial flared opening 8 in its upper portion and the axial cylindrical opening 9 in its lower portion, both of these die blocks resting upon the presser plate 10. These die blocks are suitably secured in place as by means of the wedge-shaped ring 11 which has a wedgeshaped inner face engaging a corresponding wedge-shaped outer face upon the die block 5 and a cylindrical outer face engaging .a

corresponding face upon the annular flange 12 of the spacer-l3 forming part of the bed 1. The ring 11 ls-held in place by meansof the cap bolts llwhich are threaded into the spacer 12. The upper face of the die block- 5 is preferably provided with the axial recess 14: for initially receiving the sheet metal disk when the punch 4 is elevated above the die 3.

The punch comprises the cylindrical body 15 rigidly secured to and depending from the ram 2 and having secured to its lower end the concentric ring 16 and a concentric plate '17 which is located hetween the ring and the annular shoulder 18 of the body. The ring is preferably threaded upon a reduced portion at the lower end of the body. The punch also comprises the pad 19 which .is in the nature of a plate and which preferably fits in the lower portion of the ring 16 so that the lower face of the padmay register with the lowermost face of the ring.

For the purpose of forming the steel disk into a mechanically true brake drum with a concentric brake flange, I have'provided the pad 20 which is concentric with the die 3 and is reciprocable within the aperture of this die. This pad is operated by air pressure andis normally located to contact with the disk when the punch is elevated above the disk. This pad offers sufficient resistance to the downward movement ofthe punch to firmly clamp the central portion of the disk against the punch but at the same time the resistance is such that the pad is moved downwardly with the punch. With this arrangement the central portion of the disk which eventually forms the web of the brake drum is held from distortion during the forming operation of the brake drum so'that the brake flange is .mechanically true and remains concentric when the brake drum is removed from the press. In detail, the pad 20 is mounted upon the upper end of the rod21 which extends downwardly through the bed of the,press and is secured to the upper intermediate and lower pistons 22, 23 and 24, respectively reciprocable within the axially aligned upper 1ntermediate and lowerv cylinders 25, 26 and 27, respectively. These cylinders are carried by and depend from the bed of the press. The lower end of the upper cylinder is in constant communication with the tank 28 which contains compressed air and the lower ends of the cylinders 26 and '27 are in constant conimunication'with the tank 29 which contains compressed air at a lower pressure thanthe air in the tank 28. The upper end of the cylinder 25 is adapted to be placed in communication with the tank 28, there being the control valve 30 in the pipe line forming the communication. Theupper ends of the cylinders 26 and 27 are adapted to be placed in communication'with the tank 29, there being the control valve 31 in the pipe line forming this communication.

.To remove the brake drum'from the press without distorting the brake drum, the upper pad 19 is arranged to operate as a stripper and in additionI provide a second stripper 32. The stripper 32 isarranged to take care of unequal widths of the portions of the brakev flange engaged thereby and'applies equal force thereto in disengaging the same from the ring 16 of the punch. This stripper has the links. 33 which extend upi wardly through recesses 34 in the spacer communicating' with the axial opening 35 in the spacer, these recesses-being located outside the path of. travel of the punch so that the links will not interferewith the downward movement of the punch. At the upper end of each link thereisa plunger 36'which extends transversely of the link and is yieldably forced radially inward by meansof the coil spring 37. This plunger is held in a position such that its beveled end 38 may be engaged bythe brake drum flange upon downward movement thereof to force the plunger outwardly during the travel of the brake drum flange past the plunger, after which the plunger is moved, radially inward "to engage the periphery of the ring 16 of the punch above-the brake drum flange. Each plunger is limited in its radial inward movement by suitable means which as shown comprises the nuts 39 threaded upon the outer end of the stem 40 and engageable with the wall 41 at the outer side of the link. The lower ends 'of the links are pivotally connected to the arms 42 which extend radially outward from and are preferably integral with the male member 43 of a universal mounting. This male member has a convex upper face Which-engages a concave lower face of the female member 44, this latter being secured axially in the bed 1, of the press.

The male-member 43 is normally held so that the plungers 3 8 are in the same horizontal plane by means of coil springs 45 which abut the lower face of the male member and the upper face of the plate 46, which is secured to the female member 44. Both the male and female'members of the mounting as well as the plate therebeneath have axial openings of a size to permit the passage ofthe rod 21 therethrough andalso to permit of the necessary rocking of the male member. With this arrangement it will be seen that the plungers 36 of the stripper 32 willproperly engage the upper edge of the brake drum flange, regardless of the particular locations of the portions engaged and-will apply equal pressure to these portions in stripping the brake drum from the punch.

The upper pad 19 which cooperates with the stripper 32in removing the brake drum from the punch-is secured to the rod 47 which extends upwardly throngh th'e reduced lower end portion of the body 15 and is secured to the upper andlower pistons 48 and 49,

respectively, which are reciprocable within the upper and lowercylinders 50 and '51, re-

spectively, these cylinders being axially aligned and located within the body 15. The

upper-and lower ends of these cylinders re-. spectively communicate with the .Pipes. 52 and'53which lead to a suitable four-way valve 54' for controlling the passage of compressed air to either the upper ends or lower ends of the cylinders as well as the exhaust of the air from these ends, the, arrangement being such that atsubstantially the time of engagement of the plungers36 of the strip per 32 with the upper edge of the brake drum flange, the pad 19 is held from upward movement by compressed air entering the upper ends of the cylinders 50 and 51, while the I body, 15 of the punch continues its upward movement. v

The spacer 13 is provided with the radially extending slot 55 communicating with its axial opening 35 and having awidth slightly greater than the'diameter of the brake drum and a height slightly greater than the widthof-the brake drum flange so that the brake drum may be removed below the die 3.

' To automatically remove the brake-drum after it has been stripped, I have provided,

an ejector in the nature of rods 56 which slidably-extend radially, through the portion of which link is pivotally connected to the bracket 63 upon the ram 2. 64 is a suitable guide engageable with an intermediate portion of .the link 62'and pivotally mounted upon the lever '60 during 'theup'ward movement only" of the link 62 and is solocated upon this link that it does not actuate the lever until the brake drum ha's'been stripped and the pad hasbeen moved upwardly outv of the brake drum? As shown, this dog is pivotally mounted upon the block 66 which .isadjustably secured upon the link '62 and is normally held in position to engage the lever or a. pin thereof by means of the-coil spring 67.

' The nose of this dog is beveled so that during the downward movement of the'link 62 the dog can swing while passing the lever 60, but after it has passed this lever it swings to its normal position under the influence of the spring 67 and held from further swinging in this direction'by coming into contact with a shoulder upon the block. To return the ejector rod 56 to inoperative position, I

have provided the weight 68 upon the arm 69 which is fixed uponthe pivot 58"of the bell crank arm.

In operation and with the parts in the positions shown in Figure 5 and a steel disk in place upon the die, compressed air is in the cylinders 50' and 51 below the pistons 48 and 49 to hold the pad 19 upwardly against the ring 16 upon the body 15 of the punch. Also the upper ends of the cylinders 25, 26 and 27 are in communicationwith the atmosphere by reason of the valves 30 and 31 opening to the atmosphere and at the same time closing the communication to the tanks 28'and '29. It will thus be seen that upon downward movement of the ram and the punch the pad 20 offers a resistance to this movement resulting from the pressure of air in thecylinders 25, 26 and 27 below the pistons in these cylinders so that the central portion of the steel disk is firmly clamped. When the brake drum has been drawn, as shown'in Figure 6, compressed air is allowed to enter the upper ends of the cylinders 25, 26 and 27 above the pistons in these cylinders by reason of the valves 30 and 31 placing. the tanks 28 and 29 in communication with their respective cylinders. These valves have been actuated by means of the pivoted fingers 70 and 71 upon the rod 72 which is connected to the ram 2 to be moved therewith. As a consequence, during the continued downward movement of the ram and punch, theresistance offered by the pad 20 gradually decreases untilthe ram andpunch have reached their lowermost points, atwhich time the air pressure withinthe cylinders 25, 26 and 27 and on opposite sides of the pistonstherein is balanced, the parts now being in the position shown in Figure The pad 20 now remains stationary'during the upward move ment of the ram and punchand during the initial portion of this upward movement compressed air is allowed to enter the upper ends thecylinders 50 and 51 above the pistons therein and the airin these'cylinders below these pistons is allowed to exhaust so that; the pad 19 tends to remain stationary and cooperates with the stripper 32 to disengage the brake drum from the ring ,16. upon the body 15 0f the punch. The entrance and exhaust'of theair is controlled'by the four-way valve 54'," which, during this portion of the upward movement of the ram, is actuated by the finger 73 mounted upon the rod 74, which is secured to the ram, the parts being in the position shown in Figure 8. Continued upward movement of the ram then brings the finger '75 upon the rod 72, which is also secured to the ram, into position to actuate the valve 54,.which then permits air to exhaust through the pipe 52 from the upper ends of the cylinders 50 and '51 and compressed air to enter the cylinders below the pistons therein to thereby raise the pad 19 to its normal position and out of the brakedrum, this being in position to be engaged by the ejector rod 56upon continued upward movement of the ram to be forced outwardly through the brake drum then resting upon the-pad 20 and slot 55' in the spacer 13, the parts during this portion of the operation being in the position shown by Figure 9. During the final por-' tion ofthe upward movement of the ram, the valve 30 is first actuated by the finger 76 which is mounted upon the rod 72 to place the upper end of the cylinder 25 in commu nication with the atmosphere thereby allowing the pad 20 to raiseto its original position. Then the valve 31 is actuated by the finger 77 also upon the rod 72 to close the communication between the upper ends of the cylinders 26 and 27 With the tank 29 and to place the upper ends of these cylinders in communication with the atmosphere. With this arrangement, the pad 20 is slowly raised to its original position.

10, the web of the brake drum is formed with ing the drawing operation. This-press is of the same general construction as the press With the modified press shown in Figure 110 reinforcing ribs and also with apertures durabove described. It difi'ers, however, in the .specific construction of punchand pad which have provision for forming the ribs in the web of the brake drumas well as punching.

apertures in this web. In detail, the pad ineludes the.'lower and upper sections 79 and '80, respectively, the central punch 81 and the series of concentric punches 82 surrounding the central punch. 83 1s a ring surrounding the upper section 80 and secured to the lower section 79. The central punch 81 rests upon the lower section 7 9 and has its upper end extending above the adjacent surrounding porion of the upper section 80 a. distance equal or slightly greater than the thickness of the 'brakedrum .web. The punches 82 have shoulders 84 which normally rest upon' the lower vill tral portion of the disk. against the upper section 79 sothat the tops of these punches may register-with the upper surface of the upper section 80. These punches, however, have the reduced lower ends 85 which extend downwardly through the lower section 79-and are adapted to abut the female member 86'of the universal mounting for the stripper 87.

The punch 88 which is secured to the ram'of the press has the cylindrical ring 89 which is adapted to be threaded upon the reduced lower end portion of the hollow body 90 of this punch. is adapted to cooperate with the upper surface of the ring to firmly clamp the portion of the disk or brake drum blank therebetween during the drawing of this blank. 91 is a plate rigidly secured to the ring 89 and consequently to the body of the punch, this plate being concentrically located withinthe lower end portion of the ring-89 and having the central opening 92 of the same diameter as the central punch 81. The upper surface of the upper section 80 of the pad and the lower I surface of the plate 91 and the inner portion of the lower surface of the ring 89 are shaped so that these surfaces will cooperate to form the reinforcing ribs in the brake drum web.

. In operation and upon downward movement of the ram, the ring 89 and plate 91 of the punch secured to the ram clamp the censection 80 and the ring 83 of the pad below the disk. This central portion of the disk may be fashioned at this time to form the ribs therein to approximate shape. Continued downward movement of the ram then drawsthe'disk and forms the'brake' drum flange and at the end of the downward movement the lower section 79 of the pad comes into contact with the female member 86, which is stationary,- so thatrthe web of the brake drum is bumped and the ribs therein are completely fashioned. Also during this final downward movement, the central punch '81 and other punches 82 form the shoulders in the brake drum web to receive the wheel hub and the rivets or other securing means, respectively. The metal shearedfrom the brake drum web is forced upwardly into the central hole 2 of the plate 91 and into the series of surrounding holes 93 also in this plate.

To remove the sheared metal, I have provided means carried within the hollow body 90 of the punch which is-secured to the ram. This means includes the central ejector rod 94 and the series of surrounding rods 95 which extend downwardly through the reduced lower end portion of the body and also through the plate 91. These rods are yieldably forced downwardly by suitable means such as the springs 96 and 97 so that when the brake drum has been stripped from the ring 89 upon the punch body, the sheared metal is forced back against the web of the The lower surface of the ring 89 brake drum and out of the-plate 91 so that thepress will be ready for another operatlon after the brake drum has been ejected therefrom and theram' and pad have returned to their original elevated positions.

What Iclaim as my invention is:

1. In a press, the combination with a die, a punch movable relative thereto for forming a brake drum or the like and a, stripper including a universally movable member and elements pivotally connected to said member and engageable with the flange of the brake drum or the like for disengaging the same from said punch.

2. In a press, the combination with adie, of a punch movable relative thereto for forming a brake drum or the like and a stripper for disengaging the brake drum or the like including members eng'ageableat peripheral points with an edge of the flange of the brake drum-or the like and universally movable means connected to said members for equalizing the pressure exerted by said members upon the brake drumflange.

3. In a press, the combination with a die, of a punch movable relative thereto for forming abrake drum or the like and a stripper for disengaging the brakedrum or the like including links having means engageable at peripheral points with an edge of theflange of the brake drum or the like, a stationary female member and a cooperating male member connected tosaid links.

4. In a press, the combination with a die,

'- of a punch movable relative thereto for forming a brake drum or the like, of a stripper for disengaging the brake drum or the like including links, spring pressed plungers carried by said links and engageable at peripheral points with the free edge of the flange of the brake drum or the like, a stationary female member and a cooperating male memberconnected to said links.

5. In a press, the coinbination'with a die, of a punch movable relative thereto for form ing abrake' drum or the'like and a stripper for disengaging the brake drum or the like. including links having means engageable at peripheral points with an edge of the flange of the brake. drumor the like, a' stationary female member, a cooperating male member connected to said links and means for normally, retaining said male member in a pre-.

determined position.

6. In a press, the combination with a die, of a punch movable relative thereto for form ing a brake drum or the like, a stripper below said die for disengaging the brake drum or the like from said punch, a member supporting said die and providedwith a slot therebeneath for the passage of the brake drum or the like and means for ejecting the brake drum after it has. been stripped.

7. In a press, the combination with a die, of a punch movable relative thereto for forming abrake drumv or the like, a ram carrying said punch, a stripper for disengaging the brake drum' or the like from said punch, an

ejector rod engageable with the brake drum or the like after the same has been stripped -to remove the same from the press, and

means connected to said ram for actuating said ejector rod.

-8. In a press, the combination with a die,

of a punch movable relative thereto for form-.

ing a brake drum or the like and means for disengaging the brake drum or the like from said punch including a pair of strippers respectively engageable with the flange and the web of the brake drum or the like.

9. Ina press, the combination with a die k and a reciprocable punch cooperating thereof the blank during the movement of the punch in .a direction to form' the brake drum or the like, means operable to temporarily arrest said clamping means during a portion. of'the return movement of said punch and means for disengaging the brake drum or the like from said punch during its return movement A 10. In a press, the combination with a die and a vertical reciprocable punch cooperating with said die to form-from a sheet metal blank a brake drum or the like, of a vertically movable pad cooperating with said punch to clamp the central portion of .the

' blank during the downward movement of said punch to form a brake drum or the like,

,. ing a brake drum or the like, of a stripper for and means for holding said pad normally against the blank, including a plurality of aligned cylinders having their lower ends each in constant communi'cation with a source of supply of fluid under pressure, pistons slidable within said cylinders and connected to said pad, and means controlling the inlet of fluid under pressure into the upper ends of said cylinders, said control means operating in timed relation to the downward movement of said punch, whereby equal pressures are exerted on the upper and lower sides of said pistons when said punch and pad are in their lowered positions, and means for stripping the brake drum or the like from said punch during its upward movement including a plurality of members movable transversely of the punch and engageable with the flange of the brake drum or the like.

11. In a press, the combination with a die and a vertical reciprocable punch cooperating with said die to form from asheet metal blank a brake drum or the like, of a vertically movable pad cooperating with said punch to clamp the central portion ofthe blank during the downward movement of said punch ders having their lower ends each in constant communication with a source of supply of fluid under pressure, pistons slidable within said cylinders and connected to said pad and means controlling the inlet of fluid under pressure into the upper ends of said cylinders said control means operating in timed relation to the downward movement of said punch whereby equal pressures are exerted on the upper and lower sides of said pistons when said punch and pad are in their lowered positions, means for stripping the brake drum or the like from saidpunch during its upward movement and means for ejectin the brake drum or the like after it has een stripped in cluding a rod reciprocable transversely of t: unch and engageable with the brake drum.

12. In a press, the combination with a die, of a vertically movable'punch' cooperating with said die to form a brake drum or the like, said punch including a member having a cylindrical surface and'a relatively movable pad engageable with the web of the brake drum or the like, a pad cooperating with said punch to clamp the central portion of the blank during the downward movement of said punch to form the brake drum, pressure operated means reciprocable transversely of the punch for controlling the movements of said pads, means for ejecting the brake drum or the like and ram carrying said punch and controlling the operation of said pads and ejecting means.

' 13. In a press, the combination with a die, of a punch movable relativethereto for formdisengaging the brake drum or the like ineluding a plurality of independent links, and

of the brake drum to disengage the latter from the punch. I

'15. In a press, the combination with a die,

of a punch movable relative thereto'for forming a' brake drum and the like, means engageable withthe brake drum and the like for disengaging the same from the punch, and a ,rigid evener member connected to the means aforesaid for equalizing the pressure exerted by saidmeans upon said brake drum or the li re.

16. In a press, the combination with a die, of a punch movable relative thereto for forming a brake drum and the like, a stripper including a universally movable member, and

' elements connected to said member and having portions movable relative thereto for engagin the brake drum. 1

17. n apress, the combination with a die,

of a punch movable relative thereto for forming a brake drum and the like, members engageable with the brake drum for stripping the latter from the .punch, and universally movable means connected to said members for- ,equalizing the pressure exerted by the latter 7 upon the brake drums.

In testimony whereof I aflix my signature. WILLIAM N. BOOTH. 

